The early distribution of 239Pu, 241Am and 233U in the soft tissues and skeleton of old rats. A comparative study.

1 Female and male rats of the Sprague-Dawley strain, aged about 13 months, were injected intravenously with monomeric 239Pu-(0.83 muCi/kg), 241Am-(1.48 muCi/kg) or 233U-citrate (1.53 muCi/kg) and sacrificed 7 days and 28 days after injection. 2 The wet weights and the radionuclide contents of the organs and the different bones were measured. Whereas in the soft tissue organs the radionuclide activity differs between female and male rats and between 7 days and 28 days, in the bones the relative radionuclide contents show no differences except in the femora of the 239Pu and 233U animals which are significantly different at 7 days and 28 days.